题目链接：hdu 4882 ZCC Loves Codefires

题目大意：就是CF的比赛，根据时间的推迟会相应的扣掉题目的分数，问说最少扣几分。

解题思路：相邻交换法，判断两个题目之间的比率确定前后位置。

#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;
const int maxn = 1e5+5;
typedef __int64 ll;

struct state {
    ll e, k;
}s[maxn];
int n;

bool cmp (const state& a, const state &b) {
    return a.e * b.k < a.k * b.e;
}

int main () {
    while (scanf("%d", &n) == 1 && n) {
        for (int i = 0; i < n; i++)
            scanf("%I64d", &s[i].e);
        for (int i = 0; i < n; i++)
            scanf("%I64d", &s[i].k);
        sort(s, s + n, cmp);

        ll ans = 0, t = 0;
        for (int i = 0; i < n; i++) {
            t += s[i].e;
            ans += s[i].k * t;
        }

        printf("%I64d\n", ans);
    }
    return 0;
}